The present invention relates to an apparatus suitable for delivering parts as pipette tips used in dispensing reagents or liquids to be inspected or other similar operations to intended positions for chemicobiological analysis, immunity analysis and the like, which is intended to realize effective delivery of such parts by preventing troubles in transfer due to overlapping of the parts.
In the field of the chemicobiological or immunity analysis, pipettes (dispensing nozzles) are used for dispensing liquids to be inspected and the like. In order to avoid unintentional contamination of the pipette in dispensation, a disposable tip is fitted at the distal end of the pipette, which is to be replaced with new one in every dispensation.
In usual, there is a need for previously preparing parts of this kind in bulk to perform continuous dispensing operations, so that they are generally received and stored in a hopper. To the effective replacement of these parts, moreover, it is inevitable to arrange them taken out of the hopper rapidly and regularly so as to permit these parts to be transferred to intended positions.
A hitherto used apparatus for delivering parts taken out of a hopper in regularly aligned state includes a conveyor for taking the parts one by one from the hopper where the parts are accumulated, and a transfer section for causing the parts taken by the conveyor to fall from its upper end into a gripping space so as to permit the parts to be hung in upright positions, thereby transferring the parts in alignment with one another in a row. Such an apparatus has been disclosed in Japanese Patent Application Opened No. 2000-19182, in which pipette tips are aligned and taken out of a hopper so as to be supplied to tip racks automatically.
With such a delivery apparatus, however, parts tend to overlap one upon the other as shown in FIG. 8, because the parts are accumulated in a random fashion in a hopper, and this tendency is particularly acute in tapered shaped pipette tips. When the overlapping pipette tips have arrived at the transfer section, the parts would interfere with components of the apparatus and tend to bind on the transfer passage to cause an impediment to intended dispensation.
In order to eliminate such a trouble, an attempt has been made to provide interfering members acting upon upper parts of the overlapping parts. Even with this precaution, the interfering members insufficiently operates with the overlapping parts, so that upper parts are often positioned obliquely relative to the lower parts as shown in FIG. 9 and delivered in this state to intended positions. Even if the overlapping relation of the parts is eliminated, the upper parts would tumble down from the transfer section, so that waste or useless parts occur. These are unsolved problems.
It is an object of the invention to provide an apparatus for delivering parts, which eliminates any overlapping parts to be delivered without any occurrence of waste parts, and thus, overcomes all the disadvantages of the prior art.
In order to accomplish the above object, the apparatus according to the invention for delivering parts such as pipette tips in succession includes a transfer section comprising a stepped portions for changing a transfer passage to upper and lower passages to provide a difference in height between said upper and lower passages, which is more than a size of said parts, and a separator for holding on said upper passage an upper part of at least two parts being transferred in overlapping relationship one on the other and causing the lower part of said two parts to drop by gravity onto said lower passage and continuously thereto causing said upper part itself to drop onto said lower passage.
In the apparatus constructed described above, it is particularly preferable that the separator comprises a passage extending in parallel with said transfer passage of the transfer section so as to grip only the upper part in upright hung state, and an opening located at the forward end of the passage of the separator for dropping said upper part therethrough.
Preferably, the stepped portion has an inclined passage gradually connecting the upper and lower passages.
According to a preferred embodiment of the invention, there is provided a recovery duct for returning parts removed in the transfer section to a hopper upstream of the transfer section, to prevent any occurrence of waste parts.
According to the invention it is possible to eliminate the overlapping of parts to deliver them one by one in alignment with one another, thereby preventing any stoppage of operating line due to overlapping of parts. The parts dislodged from the delivery line are restored to the hopper so that they can be supplied again by the conveyor to the transfer section without any occurrence of waste parts.
The invention will be more fully understood by referring to the following detailed specification and claims taken in connection with the appended drawings.